1. Field of the Invention
Aspects of the present invention relate to a protective circuit board and a battery pack using the same, and more particularly, to a protective circuit board and a battery pack using the same that broadens a mount region of a device and improves operability and proccessability.
2. Description of the Related Art
A secondary battery can be repeatedly used by repeating charging and discharging. Therefore, a secondary battery is economical compared to a disposable battery. These days, as a secondary battery has high capacity in a small size, secondary batteries are widely used as an electricity source of portable electronic/electric products, such as mobile phones, camcorders, notebook computers, and the like.
Examples of a secondary battery include a nickel cadmium battery, a nickel metal hydride battery, a nickel zinc battery, a lithium secondary battery, and the like. Among these batteries, a lithium secondary battery has been widely used because it is manufactured to be small in size and to have high capacity and has a high operating voltage and a high energy density per unit weight.
A lithium secondary battery can be classified into a can type and a pouch type according to a type of a cell case in which an electrode assembly is disposed. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator disposed therebetween. The can type can be further classified into a cylinder type and a prismatic type.
When a lithium secondary battery is of the can type, a cell case is generally formed of a metal, such as aluminum, and the can type may be a cylinder type, prismatic shape, or a post type having curved edges.
An opening is formed at one side of a can. After an electrode assembly and an electrolyte are disposed in the can through the opening, the opening is sealed by a cap assembly, thereby completing a secondary battery.
During manufacture or use of the secondary battery, an explosion or firing may occur due to abnormal operations, such as over-charging, over-discharging, or over-current, and the like. Therefore, the secondary battery is used, by being connected to a protective circuit board on which protection devices are mounted to prevent an accident.
At one side of the protective circuit board, there are mounted the protection devices, such as a positive temperature coefficient (PTC) thermistor, a charging/discharging device, a charging/discharging control unit, a resistor, a capacitor, and the like. At the other side of the protective circuit board, there is mounted an external connection terminal to be connected to an external set.
A secondary battery needs to be small, to have high capacity, and to secure safety. However, there are many limitations in securing a space for mounting a number of protection devices within a limited region of the protective circuit board and in securing a space for forming a high current pattern.
Moreover, even though the space for mounting a number of the protection devices and the space for forming the high current pattern are secured, there are still difficulties in mounting the protection devices and forming the high current pattern within the limited region.
Moreover, since the height of a protection device being mounted is higher than that of an electrode terminal protruding outward from the secondary battery, a height, which corresponds to the difference in the height between the protection device and the electrode terminal, needs to be compensated for so that the protection device is properly mounted.